Transport of assimilates

Transport of
Assimilates

Translocation

•The transport of sucrose
and amino acids in the
phloem

•water acts as carrier only

• Detailed

phloem
structure

• Detailed

phloem
structure

Multiple Choice

What is the structure responsible for connecting sieve elements in the phloem?

• a) Plasmodesmata

• b) Stomata

• c) Xylem vessels

• d) Phloem fibers

Multiple Choice

The movement of assimilates in the phloem from source to sink is known as:

• a) Transpiration

• b) Translocation

• c) Osmosis

• d) Diffusion

Which has been
synthesized by
the plant?

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Source

●the part where
sucrose & amino
acids are
manufactured

Sink

●the part where sucrose
& amino acids are
delivered to

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Source

●the mature, green
parts of a plant

These are the parts where:

●photosynthesis occurs

●sucrose is assembled

●amino acids are
assembled

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Sink

●the parts where
sucrose & amino
acid are used or
stored

Multiple Choice

Which of the following is an example of a sink in plants?

a) Developing leaves

b) Developing fruits

c) Root tips

d) Mature roots

• a) Developing leaves

• b) Developing fruits

• c) Root tips

• d) Mature roots

Multiple Choice

What is the driving force behind the movement of water in the xylem?

• a) Active transport

• b) Transpiration pull

• c) Osmosis

• d) Root pressure

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Sink

●the parts where
sucrose & amino
acid are used or
stored

In the shoot:

●sucrose converted to
cellulose or as energy
source

●amino acids used for
production of new shoot
cells

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Sink

●the parts where
sucrose & amino
acid are used or
stored

In the flower:

●sucrose is used to produce
nectar or as energy source

●amino acids are used to
produce protein pigments for
flower color

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Sink

●the parts where
sucrose & amino
acid are used or
stored

In the fruit:

●sucrose stored, converted to
other forms or as energy
source

●amino acids are used to
produce protein & seed
components

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Sink

●the parts where
sucrose & amino
acid are used or
stored

In the trunk/stem:

●sucrose is stored, converted
to lignin, or used as energy
source

●amino acids are used to
create protein for phloem
cells

Multiple Choice

Which structure in the root is responsible for the uptake of water and minerals from the soil?

• a) Root hairs

• b) Cortex

• c) Endodermis

• d) Pericycle

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Sink

●the parts where
sucrose & amino
acid are used or
stored

●table sugar comes from stored
sucrose inside the sugarcane
stem.

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Sink

●the parts where
sucrose & amino
acid are used or
stored

In the roots:

●sucrose is stored or used as
energy source

●amino acids are used to
produce new cells for root
elongation

Translocation

•aside from phloem, it involves plant parts serving as sources &
sinks

Sink

●the parts where
sucrose & amino
acid are used or
stored

●in potato tubers, sucrose is
converted to starch for storage.

Multiple Choice

Which of the following is an example of a source in plants?

• a) Developing leaves

• b) Developing fruits

• c) Root tips

• d) Mature roots

Multiple Choice

Which of the following is NOT a characteristic of sieve tubes in the phloem?

• a) Lack of nuclei

• b) Presence of perforated sieve plates

• c) Thickened cell walls

• d) Long and cylindrical shape

Why do plants store sugars?

•so that they have a backup for when
conditions become unfavorable for
photosynthesis.

deciduous trees lose
their leaves during winter
and must store as much
sugars as possible
before winter season.

Why do plants store sugars?

•so that they have a backup for when
conditions become unfavorable for
photosynthesis.

Maple syrup comes from
the stored sucrose in the
trunk of the maple tree.

During winter, roles are reversed!

•sinks in summer becomes sources in
winter and vice versa.

sink

sink

source

source

sink

SUMMER

WINTER

Multiple Choice

1. Which of the following is NOT a component of the phloem tissue?
   

• 1. a) Sieve tubes

• 1. b) Companion cells

• 1. c) Tracheids

• Loading and

Unloading in
the phloem

•
Active Transport of sucrose into companion cell using a
carrier protein called H+ ion – sucrose co-transporter

How can you observe Transpiration?

•what is a simple experiment you can do to prove that water
evaporates from leaves?

You can trap the water vapor
evaporating from leaves.

●1. Cover a plant or a branch of a
plant with plastic and seal it off
from the outside environment

●2. Check for the for moisture
present inside the plastic after 24
hours.

condensed water

vapor

Multiple Choice

Which of the following is NOT involved in the loading of assimilates into the phloem?

• a) Active transport

• b) Diffusion

• c) Symplastic movement

• d) Apoplastic movement

Multiple Choice

Which of the following is NOT a factor affecting phloem transport?

• a) Temperature

• b) Humidity

• c) Light intensity

• d) Gravity

Multiple Choice

What is the function of companion cells in the phloem?

a) Storage of sugars

b) Protection of sieve tubes

c) Transport of water

d) Facilitation of loading and unloading of assimilates

• a) Storage of sugars

• b) Protection of sieve tubes

• c) Transport of water

• d) Facilitation of loading and unloading of assimilates